Our epidemiologic studies of senile cataract have identified ocular UV-B exposure as a major risk factor for cortical cataract and smoking as a risk factor for nuclear cataract. We studied watermen who work on Chesapeake Bay. They form an occupational group that is unique because their occupational stability allows for assessment of the ocular UV-B exposure they acquire over their adult lives. In 1985, we collected data on a population-based sample of 838 watermen over age 30. Detailed exposure histories and data on other potential risk factors were collected as well as photographs of the lens and macula. We now propose to reexamine our original group in 1990 to characterize the natural history, both incidence and rate of progression, of the various types of lens opacities and macular changes. Specifically we aim to: 1. Determine the 5-year incidence and rate of progression of lens opacities in the study population. 2. Assess the association of previously identified risk factors with the incidence of lens changes (for example UV-B exposure and smoking) and with the rate of progression of these changes. 3. Determine the 5-year incidence and rate of progression of age-related macular degeneration (AMD), assess the prognostic significance of early macular changes, and explore the role of UV-B exposure in the progression of AMD. These data will provide important population-based information on the natural history of lens opacities and macular degeneration that will further increase our understanding of these diseases and guide both clinical practice and future clinical studies.